Electromagnetic relay



G F DALY ELECTROMAGNETIC RELAY Filed July 2l, 1950 +P ZQ Nov., 18, 1952 ow-Mavic 660591@ fj? BZ c?? wn ""f Patented Nov. 18, 1952 UNITED STATES PATENT OFFICE Claims.

This inventionrelates to relaysparticularly of the low voltage signal type, and has for its primary object the provision of an improved relay in which the working parts are contained within a hollow spool which is enclosed within a housing therefor seas to protect it from dirt, oil, and other surrounding matter.

It is a further object to provide a simple, eicient, and dependable relay which will take up less space than a comparable relay of conventional construction; a novel and improved electromagnetic relay in which the armature or" the relay constitutes all or a major portion of the magnetic core of the relay; and a mounting for the essential parts of the relay in the general form ofA a hollow spool, togetherwith an enclosing housing therefor; and a single means for securing the spool within the housing kserving to hold also certain of `the relay components within the spool.

Various other objects, advantages and features of the invention will be apparent from the following description when taken in conjunction with the accompanying drawing wherein a preferred embodiment is set forth for purposes of illustration in the manner following:

Figure 1 is a longitudinal vertical section through a relay constructed in accordance with this invention;

Fig. 2 is a transverse section therethrough, taken on line 2*2 of Fig. 1;

Fig. 3 is a horizontal section therethrough, taken on line 3-3 of Fig. l; v

Fig.v 4 is a transverse section therethrough, taken on line 4 4 of Fig. 1;

Fig. 5 is a schematic diagram of the relay in a typical relay circuit;

Fig. 6 is a fragmentary vertical section of the relay when modied in the one respect of having its cross sectional contour square instead of round; and

Fig. 7 is a transverse sectional View, taken on line 1 1 of Fig. 6.

There is shown in Figs. 1-4 a form for the relay coil in the nature of a spool having vfront and rear cylindrical heads A and B interconnected by a hollow hub C having a longitudinally extending chamber l. Such a spool structure is adapted to support the wire windings W constituting the coil of the relay, and to be accommodated within a cylindrical housing E' closed by a wall i2 at its end which is proximate to the front head A. The rear spool head B normally lies substantially iiush with the open end of the housing and occupies the full areathereof so as to provide a closure therefor.

Within the rear head'B is provided a. diametrically extending chamber l5 aligned with a like chamber I8 in the front head A, each chamber being closed at one end-the top as herein shown. These two head chambers communicate at points medially of their ends with the hub chamber l), and oppositely ofthe hub an opening Il is provided in the outer wall of the front head A. The cross sectional form of these head chambers is a matter of choice, but for simplicity in construction and illustration a round'cross section is indicated.

Positioned within the upper end portion of thel rear chamber l5 is a cylindrical terminal blockA i3 Whose lower face depends slightly below the top face of the hub chamber lll. A screw I9 having a threaded shank is entered through the outer end of the rear head B to engage with av tapped hole in the terminal block therewithin and provide a securing means therefor. The head 20 of this screw engages a terminal iitting 2| which is carried on the outer wall of the rear head B.

Within the chamber I5 in the front head A is a second terminal block 25 also secured in place by the threaded shank of a screw 26 which is entered into a tapped hole therein, the screw head 21 which is disposed exteriorly of the housing wall I2 being engaged with a terminal ntting 28 to secure the same in place. The lower face of the terminal block is approximately aligned with the top face of the hub chamber lil.

There is also accommodated within the rear head chamber i5 a cylindrical clamping block 35 formed therethrough with an axial hole 36 for reception of the shank of a locking screw 3'! whose head 38 is engaged with the block at its bottom end. The upper end portion of the screw shank which is threaded is entered into a tappen` socket in the terminal block' i8 thereabove to engage therewith, thereby to secure the clamping block 35 xedly in place. Another cylindrical terminal blocklll'! is positioned in the front head chamber I6. The top face of this block is approximately aligned with the lower face of the hub chamber I0. A screw 4I which is extended through the wall I2 is entered into a tapped hole in the block 4i) ior'screw-threaded engagement therewith, the screw head 42 remaining exteriorly of the housing to engage a terminal fitting 43 which is thereby secured to the housing end wall i2. At the rear end of the spool connection may be made with a mounting bracket M by means of screws i6 which pass therethrough to enter tapped holes in the outer wall of the head B.

Within the hub. chamber I9 is extended a elongated bar 50 of soit iron or the like. A leaf spring 5| which is connected by a rivet 52 to the -top face of the armature bar extends lengthwise thereof and beyond its rear end at 53 to provide a hinge which is positioned intermediately of the upper and lower blocks I8 and 35 to be clamped xedly in position therebetween when the anchoring screw 3l which passes therethrough is rotatively advanced to its nal position. The leaf spring which is thereby secured ixedly in place provides a hinge-spring mounting for the armature bar such that its free end at the front has capacity to swing down and away from the normal up position of Fig. 1.

A contact 5d is carried on the lower face of the upper block 25 at a point oppositely of a coacting contact 55 which is carried at the top end of a pin 5B which extends vertically through the armature bar 50; and a contact 5l is also :carried at the lower end o the pin 56 oppositely fof a coacting'contact 58 on the top face of the :block Through a lead a an electrical contnection from the upper terminal block 25 is estab- 'lished with a lamp L, or other mechanism to be 'electrically energized (see Fig. 5), the lamp being in electrical connection through leads b, c, and d 'with one side of a current source S. The lower `'terminal block d@ is in electrical connection through a lead e with a second lamp L (or other electrically energized mechanism) which connects electrically with the same current source S through the leads c and d. From the other side of the current source a lead f connects with the upper terminal block I8 which is in electrical connection with the armature bar 50. A lead y, which is tapped into the lead f and provided with a switch h, connects with one end of the coil W whose other end is connected with the lead i which is tapped into the lead b. The coil is thereby placed in circuit with the current source S. With the switch h in open position, the circuit remains closed through the armature 50, contacts 54 and 55 and leads a-d to energize the lamp L, but when the switch is operated to closed position, current ows through the coil W to lower the armature 50 and establish an alternate circuit through the leads e, c, and i to energize the lamp L.

The structure of the coil spool may advantageously be produced in one piece from a plastic material having an insulation value which is adequate to prevent current leakage between the several current conducting parts. When assembled and in use, the relay components are maintained iixedly in position and completely protected within the chambers wherein they are located, and within the enclosing housing that is provided for the spool structure as a whole. The lower blocks 35 and 40 are desirably produced from magnetic materialsoft iron, for example, whereas the terminal blocks i3 and 25 are of non-magnetic material. The cross sectional form of the relay may lbe variously contoured. A square structure is indicated in Figs. 6 and 7 wherein the various parts which correspond to those already described in connection with Figs. l-4 bear the same reference characters with a prime added thereto.

Normally the armature spring 5l tends to urge the armature 50 in the up direction whereby to maintain the contacts 54 and 55 normally in engagement. However, when the current flows through the coil W it sets up in the chamber I0 a magnetic eld having a flux whose major porma'gnetic armature in the general form of an tion ows through lthe magnetic blocks 40 and 35 to the armature 50 which is attracted to the magnetic block 4i), thus separating the upper contacts 5d and 55 and bringing the lower contacts 5'! and 58 into engagement. There is sufcient space, angular or otherwise, between the armature bar 50 and the magnetic block 35 to permit swinging movement of the armature through its operative range. The head 53 of the spring 5| may be tted snugly within the space between the terminal block i8 and the magnetic block 35 to prevent sidewise movement of the armature, and the rivet and pin connections 52 and 56 between the spring and armature serve eiectively to prevent one from swinging relative to the other.

The concentration of magnetic ilux in the armature is high inasmuch as this armature also serves as the core of the relay, being situated in the strongest part of the magnetic eld. The force of attraction `between the armature 50 and the magnetic block 45 is therefore relatively strong, even for a small current owing through the coil W. The flux is intensified by the magnetic block 35 which provides a magnetic path around the rear end of the coil W to the armature 55, and as a result the armature is sensitively responsive to a very weak current when flowing through the coil.

The relay herein described has proved dependable in operation over a prolonged period of time and with no maintenance attention. In these respects it is advantageous over relays in which the working parts are exterior to the coil or winding. My present relay is also more eiicient since the movablearmature is disposed in a portion of the magnetic eld where the magnetism is strongest, viz. Valong the axis` of the coil.

I claim:

l` In an electromagnetic relay, a spool having spaced heads with diametrically extending chambers interconnected by a hub with an elongated axial chamber in communication with those in the heads, a coil wound upon the hub between the heads of the spool, an elongated armature extended longitudinally within the axial chamber of the hub, a pair of spaced terminal blocks positioned within one head chamber and separated oppositely of the hub chamber to accommodate therebetween one end of the armature, a terminal block iixedly secured in the other Y head chamber disposed wholly to one side of the armature, a magnetic block also positioned slidably within the head chamber last named and extended beyond the proximate end of the armature in lapping relation thereto, a leaf spring aiiixed to the armature and provided beyond one of the armature ends with an extension disposed between the terminal and magnetic blocks in the head chamber last named, screw means extended through the magnetic block and into the adjacent fixed terminal block for threaded engagement therewith and acting to secure the magnetic block thereto and clamp the leaf spring extension therebetween to provide for the armature a spring hinge mounting which urges the armature free end toward one of the two spaced terminal blocks adjacent thereto, a pair of contacts carried at the armature free end and other coacting contacts opposite thereto carried on the adjacent terminal blocks, and switch-controlled electrical circuit connections between a current source and the coil and between the armature and each set of contacts separately for operation alternately of a pair of electrically energized devices.

2. In an electromagnetic relay, a spool having spaced heads with diametrically extended chambers interconnected by a hub with an elongated axial chamber in communication with those in the heads, a coil wound upon the hub, an elongated armature extended longitudinally within the axial chamber of the hub and into one of the head chambers, a pair of spaced contactsupporting blocks within the head chamber last named arranged to receive alternately contact from the proximate armature end when it is moved therebetween, a pair of blocks, arranged end to end, one fixed and the other movable toward the rst, in the other head chamber, a leaf spring affixed to the armature and extending beyond one end thereof between the two blocks last named to be engaged thereby, screw means interconnecting the two blocks last named and the leaf spring portion therebetween and acting, when rotatively advanced, to advance one block toward the other to engage with pressure the leaf spring portion therebetween whereby to provide a tensioned mounting for one end of the armature whose opposite end is biased into engagement with one of the spaced contactsupporting blocks, and switch-controlled electrical circuit connections between a currentl source and the coil and between the armature and each contact-supporting block separately for operation alternately of a pair of electrically energized devices.

3. In an electromagnetic relay, a spool having spaced heads with chambers extending transversely of the spool axis and each opening out upon one side of the head, a hub interconnecting the two heads and formed with an elongated axial chamber in communication with those in the heads, a coil wound upon the hub, an elongated armature extended longitudinally within the axial chamber of the hub and into one of the head chambers, a pair of spaced contact-supporting blocks within the head chamber last named arranged to receive alternately contact from the proximate armature end when moved therebetween, a pair of blocks, one fixed and the other movable toward the rst, in the other head chamber, a leaf spring aixed to the armature and extending beyond one end thereof between the two blocks last named to be engaged thereby, screw means interconnecting the two blocks last named and the leaf spring portion therebetween and acting, when rotatively advanced, to advance one block toward the other to engage with pressure the leaf spring portion therebetween whereby to provide a tensioned mounting for one end of the armature whose opposite end is biased into engagement with one of the spaced contactsupporting blocks, a housing closed'at one end and open at the other providing an enclosure for the relay spool and a closure for the open ends of the head chambers, screw means traversing the closed end of the housing and entered into the contact-supporting blocks of the proximate head for threaded engagement therewith to secure the blocks fixedly in spaced positions therewithin and also secure the relay spool fix- 6 edly in position within the housing, and switchcontrolled electrical circuit connections between a current source and the coil and between the armature and each contact-supporting block separately for operation alternately of a pair of electrically energized devices.

4. In an electromagnetic relay, a spool having spaced heads with chambers extending transversely of the spool axis and each opening out at one side of the head, a hub interconnecting the two heads and formed with an axial chamber communicating with those in the heads, a coil wound around the hub between the heads of the spool, a pair of spaced contact-supporting blocks in the chamber of one head, an elongated armature within the axial chamber of the hub having a spring mounting at one of its ends whereby its opposite end is free to move between the adjacent contact-supporting blocks, a housing closed at one end and open at the other providing an enclosure for the relay spool one of whose heads is disposed at the housing open end to provide a closure therefor, the housing also providing a closure for the open ends of the head chambers, and screw means traversing the closed end of the housing and entered into the contact-supporting blocks of the proximate head for threaded engagement therewith to secure the blocks xedly in position therewithin and also secure the relay spool xedly in position within the housing.

5. In an electromagnetic relay, a spool having spaced chambered heads interconnected by an axially hollow hub, the head chambers being disposed transversely of the spool axis and opening out upon one side of the spool, a coil wound around the hub between the heads of the spool, a pair of spaced contact-supporting blocks in the chamber of one head, an elongated armature within the hub having a spring mounting'at one of its ends whereby its opposite end is free to move between the adjacent contact-supporting blocks, a housing closed at one end and open at the other providing an enclosure for the relay spool and for the open ends of the chambers of its two heads, one of the spool heads being normally disposed at the housing open end to provide a closure therefor, and screw means traversing the closed end of the housing and entered into the contact-supporting blocks of the proximate head for threaded engagement therewith to secure the blocks xedly in position therewithin and also secure the relay spool nxedly in position within the housing.

GEORGE F. DALY.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,029,267 Leece et al Jan. 23, 1936 2,401,347 Hansen June 4, 1946 2,471,594 Weightman May 31, 1949 2,486,394 Eannarino Nov. l, 1949 2,570,315 Brewer Oct. 9, 1951 

